As well as the spectrum idea, another useful way of thinking about how we provide subject access to information resources is by considering where the words or text we search on come from. Derived indexing takes words (derives them) from the document. Assigned indexing takes words from somewhere else (for example, from a list of subject headings or a thesaurus) and assigns them to the document.

I really need to know the difference between .scisshl and .SCot ( as well as provenence)

Time to read Chapter 6: Subject access conceptspg99

This has traditionally involved deciding what the information resource is about, translating that into terms (words and phrases) or symbols which represent the subject, and providing access to these terms and symbols through the library information retrieval system.pg 100: Subject area crossroads, three paths diverge:

post coordination:search stage (joined after the the creation of entry, in boolean search)

All judged by Relevance, Recall and precision.

Keywords

Subject access

Literary warrant

Indexing language

Pre-coordination

Controlled vocabulary

Post-coordination

Derived indexing

Natural language

Assigned indexing

Free indexing language

Exhaustivity

Classification scheme

A couple of the terms that may cause problems are pre-coordination and post-coordination. Harvey and Hider’s distinction is that single-concept terms can either be combined (coordinated) at the indexing stage (pre-coordination) or at the search stage (post-coordination). Bear in mind that the indexing in many computer systems allows users to search certain fields for keywords and phrases, as well as providing displays of precoordinated strings for browsing.

Ok, 1, I think I answered above, as with 2. And 3 is on page 103 of the text.

Exercise 1 – Review questions

1. Explain the difference between derived indexing and assigned indexing.

2. Explain the concept of exhaustivity.

3. Outline the main weaknesses associated with the use of a controlled vocabulary.